We look at the division of 15945759 by 503 
The aim is to understand the frequency of 503 in 15945759.

Advancing to step 1:
503 goes into 1 0 times with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Take the next digit (5) from the dividend and append it to 1, then repeat: 15 / 503

Moving on to step 2:
If we divide 15 by 503, we get 0 and a remainder of 15.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 15 after subtracting 0 from 15.
Grab the next digit (9) from the dividend, add it to 15, then carry on: 159 / 503

Moving on to step 3:
503 can be fit into 159 0 times, resulting in a remainder of 159.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 159 to get 159.
Append the next digit (4) from the dividend to 159 and continue with: 1594 / 503

On to step 4:
503 can be fit into 1594 3 times, resulting in a remainder of 85.
The next digit of our result is 3. 
Result so far: 3.0
Subtract 1509 from 1594 to get 85.
Append the next digit (5) from the dividend to 85 and continue with: 855 / 503

On to step 5:
The number 503 fits into 855 1 times, leaving a remainder of 352.
The next digit of our result is 1. 
Result so far: 31.0
Subtract 503 from 855 to get 352.
Bring next digit (7) of the dividend behind the 352 and repeat the process: 3527 / 503

Advancing to step 6:
If we divide 3527 by 503, we get 7 and a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 317.0
If we take 3521 away from 3527, we end up with 6.
Include the next digit (5) from the dividend after 6, then repeat: 65 / 503

Let's proceed to step 7:
When dividing 65 by 503, we get 0 with a remainder of 65.
The number 0 becomes the next digit in our result. 
Result so far: 3170.0
Subtracting 0 from 65 leaves us with 65.
Include the next digit (9) from the dividend after 65, then repeat: 659 / 503

Advancing to step 8:
When dividing 659 by 503, we get 1 with a remainder of 156.
Record the quotient 1 as the next digit in the result. 
Result so far: 31701.0
Subtract 503 from 659 to get 156.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1560, and continue the process.

Let's proceed to step 9:
The number 503 fits into 1560 3 times, leaving a remainder of 51.
Use 3 as the next digit of our solution. 
Result so far: 31701.3
Subtracting 1509 from 1560 leaves us with 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Moving on to step 10:
503 goes into 510 1 times with a remainder of 7.
Use 1 as the next digit of our solution. 
Result so far: 31701.31
Subtracting 503 from 510 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Moving on to step 11:
If we divide 70 by 503, we get 0 and a remainder of 70.
The number 0 becomes the next digit in our result. 
Result so far: 31701.31
Subtracting 0 from 70 leaves us with 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 700, and continue the process.

Moving on to step 12:
503 goes into 700 1 times with a remainder of 197.
Use 1 as the next digit of our solution. 
Result so far: 31701.3101
Deduct 503 from 700 and we're left with 197.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1970, and continue the process.

Let's proceed to step 13:
1970 divided by 503 is 3 with a remainder of 461.
Record the quotient 3 as the next digit in the result. 
Result so far: 31701.31013
Subtracting 1509 from 1970 leaves us with 461.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4610, and continue the process.

Going ahead to step 14:
The number 503 fits into 4610 9 times, leaving a remainder of 83.
Use 9 as the next digit of our solution. 
Result so far: 31701.310139
Subtracting 4527 from 4610 leaves us with 83.
Since there are no more digits in the dividend, we add a zero to the remainder making it 830, and continue the process.

Moving on to step 15:
503 goes into 830 1 times with a remainder of 327.
Use 1 as the next digit of our solution. 
Result so far: 31701.3101391
If we take 503 away from 830, we end up with 327.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3270, and continue the process.

On to step 16:
503 goes into 3270 6 times with a remainder of 252.
Use 6 as the next digit of our solution. 
Result so far: 31701.31013916
If we take 3018 away from 3270, we end up with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

In conclusion, the division gives 31701.31013916 with a balance of 2.52e-07.